feat(egress): replace log bool with integer log levels (0/1/2)

Level 0 (off, default): no stderr output beyond boot line.
Level 1 (blocks): each block/warn emitted as JSON with reason and
request context (host, method, path, response_status for inbound).
Level 2 (full): level-1 events + egress_request and egress_response
JSON lines for every forwarded connection.

Block logging at level 1+ replaces the previous plain-text stderr write.
DLP warn logging is also gated on level 1+. All block call sites now pass
_req_ctx(flow) so the blocked request is visible in the log entry.
Boot message shows log level label (off/blocks/full).

Adds PRD 0053 documenting wire format, manifest format, and all log event
shapes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot_bottle/egress.py

@@ -62,7 +62,7 @@ class EgressPlan:
     egress_network: str = ""
     mitmproxy_ca_host_path: Path = Path()
     mitmproxy_ca_cert_only_host_path: Path = Path()
-    log: bool = False
+    log: int = 0
 
 
 def egress_manifest_routes(
@@ -192,11 +192,11 @@ def _route_to_yaml_fields(r: Route) -> dict[str, object]:
 def egress_render_routes(
     routes: tuple[EgressRoute, ...],
     *,
-    log: bool = False,
+    log: int = 0,
 ) -> str:
     lines: list[str] = []
     if log:
-        lines.append("log: true")
+        lines.append(f"log: {log}")
     lines.append("routes:")
     if not routes:
         lines[-1] = "routes: []"